1) The V8’s still great

The new sixth-gen M5 packs the same twin-turbocharged 4.4-litre V8 as its predecessor (the S63B44T4, if you’re a code fetishist) but it’s now even more powerful, and less thirsty.

New turbos and higher injection pressures have pushed power to more than four times that of the entry-level 5-series. BMW hasn’t confirmed power figures yet, but our understanding is it’s somewhere close to 608bhp at 6000rpm, with max torque 553lb ft from 3000rpm.

For comparison, the most powerful version of the previous M5, the ‘30 Jahre’ run-out model, developed 591bhp.

2) More gearbox speeds, and more speed full stop

It’s now hooked up to a conventional auto gearbox rather than the previous dual-clutch, which couldn’t cope with the increased torque. The new ‘M Steptronic’ gearbox is better equipped to cope with the new all-wheel-drive system, and offers eight forward speeds to the DCT’s seven.

The new ’box helps kerb fuel consumption and emissions, too, to the tune of a claimed 26.9mpg combined. We can tell you some rather juicy performance figures:

3.3sec 0-62mph

…and 12.5sec 0-125mph

Top speed limited to 155mph, but optional M driver’s package takes it to 197mph

3) It has many, many driving modes…

Had God given man three eyes and seven digits per hand, the ergonomic overkill of the new M5 would be fine.

Fabric and black tape hides many of the switches and buttons in the camouflaged prototype driven here, but the knobbly gear selector suffers from severe button rash.

M1 and M2 thumb switches on the horizontal spokes of the steering wheel activate two personalised set-ups, and there are also three separate buttons to switch modes for the drivetrain, dampers and steering. Plus a sub-menu for the various levels of stability control assistance, and two-wheel-drive mode – more on which in a bit.

Sounds complicated, and it is. It aims to offer the best of all worlds, but what it gains in cleverness it loses in user-friendliness.

4) …and those modes work very well

When you first press the V8’s starter button (hidden behind a piece of fabric in this car’s heavily disguised interior), the traction control and stability control programs are switched to their most cautious settings by default, and the 4wd system is programmed for optimum grip and stabililty.

In normal driving mode, the M5 stays rear-wheel-drive most of the time to save fuel, only bringing the front axle into play when necessary.

Switching to MDM (M Dynamic Mode) channels more torque to the rear wheels and relaxes the stability control a little, but it still errs on the side of caution.

4WD Sport pushes the handling balance rearward, for your first sip of power oversteer, and then there’s M xDrive (DSC off), which fully relaxes the electronic guardian angels, and relies on your wits and the all-wheel-drive system to keep you out of trouble.

And then, there’s a further 2wd mode, which sends all of the M5’s torque (as much as 553lb ft at its peak) to the rear wheels, while the electronically controlled differential has the ability to lock up 100%.

‘We assume that buyers who select two wheel drive want all the fun and no supervision’ says M division boss Frank van Meel.

In this mode the handling is balanced enough, but you need quick reflexes to stay on top of it. One for the track only.

5) All-wheel-drive hasn’t ruined the M5. It’s saved it

The old M5 needed to get its tyres warm to do its best work, and even then struggled to put its power down without turning the rear 20-inchers into mobile bonfires.

Not any more: the new M5 can carve, or crab, through corners at whatever angle you choose, yet still finds plenty of traction at corner exit. It’s not only capable of faster cornering speeds, but more complete control.

In MDM mode, it’s easier to drift than its rear-wheel-drive predecessor, and faster too.

Following racing driver Timo Glock in an M4 GTS in the rain on BMW’s handling circuit, the M5 can close the gap to it in places on this wet circuit, thanks to its extra driven axle, and extra 150bhp.

Don’t be surprised to see M xDrive appear on the next-gen M3 and M4…

6) It doesn’t feel like a big brother of the M3

It could have, but instead it carves out its own niche. Based on our test track experience, it feels more like a muscular GT, or a high-speed executive express.

Good enough to vanquish the Mercedes-AMG E63 S? We’ll have to wait a few more months for the final verdict.